Once the rainwater has collected into a tank, it is easily channeled for use in the garden, driveway area or for topping up the swimming pool among other uses. The homeowner can gain more benefits by rooting the water to the toilets or to the laundry area. A City or suburban family can save its mains water needs by about 70% if it can use rainwater for flushing, washing clothes and watering the lawn.
The toilet flushing process usually takes up the bulk of the water in most houses. About 12 liters are used up on every flush and therefore supplementing the mains water supply with a rainwater system will lead to saving up greatly on water. One person uses about 30 liters of water in a single day and this translates to about 210 liters in a week. If an average house has four members, it means that the home needs about 840 liters of water in a week just to operate in normal conditions. The home can always switch back to mains water once the rainwater tank is empty.
Combined with the water saved from flushing, having the water utilized in the laundry machines or for handwashing can also save much water. It is easy to connect the laundry machine to the tank water supply. A typical wash can take up to 150 litres of water in one load. Many houses will do more than 5 loads in a single week and that means a lot of the water in the home is meant for washing clothes and flushing the toilet. Some houses use much more water since they rely on handwashes for the clothes. Using rainwater in such situations will be convenient since it is a way to wash clothes without relying on mains water and without relying on electric power if the family lives off the grid.
Watering the garden with rainwater can save the household the money that would have otherwise been incurred in maintaining a green lawn. In some countries, watering the lawn with the town’s water supply is forbidden on certain days. However, someone is free to use rainwater anytime he wants because it was not supplied by the authorities.